Chapter 3: Coordinate Geometry

Exercise 3.3 - Plotting Points

Exercise 3.3 - Detailed Solutions


Question 1: Which quadrant?

Method:

Check signs of coordinates!

CoordinatesSignsQuadrant
(2,3)(2, 3)(+,+)(+, +)I
(3,2)(-3, 2)(,+)(-, +)II
(4,3)(-4, -3)(,)(-, -)III
(3,1)(3, -1)(+,)(+, -)IV

Question 2: Plot and identify

(x,y)(x, y) where x<0x < 0 and y>0y > 0

x<0x < 0 means x is negative y>0y > 0 means y is positive

Signs: (,+)(-, +)Quadrant II

(x,y)(x, y) where x>0x > 0 and y<0y < 0

Signs: (+,)(+, -)Quadrant IV


Question 3: Rectangle from Points

Points: A(1,3)A(-1, 3), B(1,4)B(-1, -4), C(5,4)C(5, -4), D(5,3)D(5, 3)

Step 1: Plot the points

  • A is in Quadrant II
  • B is in Quadrant III
  • C is in Quadrant IV
  • D is in Quadrant I

Step 2: Join them in order

Step 3: Identify the shape The figure is a RECTANGLE

Step 4: Find dimensions

  • Length (AB or CD): 3(4)=7|3 - (-4)| = 7 units
  • Width (BC or AD): 5(1)=6|5 - (-1)| = 6 units

Area = 7 × 6 = 42 square units

Visualizer
Coordinate Plane
XYOA(-1, 3)B(-1, -4)C(5, -4)D(5, 3)Q I (+,+)Q II (-,+)Q III (-,-)Q IV (+,-)
Point A: (-1, 3)
Quadrant II

Interactive Visualization